Effect of 1-butanol on the surface structure of ionic micelles and location of its solubilization site: Electron spin echo modulation study with x-doxylstearic acid spin probes

Electron spin echo modulation studies with a series of x-doxylstearic acids (x = 5, 7, 10, 12, and 16) have been carried out for sodium- and tetramethylammonium dodecylsulfate and dodecyltrimethylammonium chloride frozen micellar solutions containing protiated and perdeuterated 1-butanol. Modulation effects due to nitroxide interactions with deuterium in water and butanol have been measured versus doxyl group position. The effect of 1-butanol on the micellar surface and internal micellar structure has been evaluated and the average location of 1-butanol in these micelles has been deduced to be in the outer annulus of the micelle core.